Wouldn’t it be nifty to just drape a damp towel around your neck and have it effectively cool you down? Cooling towels require no electricity and can be re-used for a very long time. It sounds like a great idea — but how well do they actually work?
I’ve looked at towels before (and talked a bit about them in yesterday’s article) so here’s my current take on them as a prep.
Since The Place needed some love (in the form of manual labor), the cabin’s got no electricity, and the temps were going to be pushing three digits, it seemed like a great time to test one out.
What are cooling towels and how do they work?
Cooling towels are just cloth made of a fabric that wicks up quite a lot of water then helps it evaporate quickly. It takes energy to make water evaporate, so when the water leaves, heat energy is lost. On a hot day, about 44,000 J of heat energy is removed for every kg of water vaporized. (1)
To use a cooling towel, you get it really wet, wring it out, and lay it on you. It’s your body heat that is removed when the water evaporates. Couldn’t be easier.
Theory’s nice and all, but how much does it really help under the conditions a prepper might need it? A day of manual labor followed by a night with no AC at The Place seemed like a great time to do some experimenting. The towel I used was pretty standard and seemed to me about as efficient as other models I’ve used in the past. It was made of polyvinyl alcohol.
This cooling towel is a lot like the one I tested (which was a pretty run of the mill specimen).
Round 1: Cooling Towel vs. Mowing and Gardening
First observation: These towels soak up a lot of water. The enclosed information claims it can soak up eight times its own weight. I wrung about half of that out, as water dripping off doesn’t remove nearly as much heat as water evaporating off.
This is the standard usage; the towel doesn’t slip much but doesn’t help that much either.
Second observation: The coolest place to put the towel is on the head like an Arabic head scarf (almost like desert dwellers know how to keep their cool), but it tends to slip off. A kerchief was needed to keep it in place; or go with the next best option of towel around the neck.
Heads have a lot of blood flow and sun exposure, so they are the best spot to cool.
Results: The towel helped, but not a lot. It felt cool on the skin, especially if I turned it frequently, but my overall experience was a pretty normal “Yep, still really hot pushing this mower up hills on a July afternoon.”
Round 2: Cooling Towel + Shade vs. 95 F day
Now it was time to sit, hydrate, and do some paperwork. Being still, I could fan the re-wetted towel out over neck and chest as I sat. I had good shade but only a tiny breeze. Interspersing periods of towel and no towel served as my crude control group.
Results: Minor edge to comfort with the towel. The evaporation of the towel seemed a little more efficient than my normal sweat evaporation, in other words.
Round 3: Cooling Towel to Improve Sleep
I’m ok without AC most of the time, but I admit to missing it on hot nights when I’m trying to go to sleep. I had hopes that the towel would improve the situation.
Third observation: The towel is not effective in a humid, still air environment. Re-wetted and draped over my legs for maximum skin exposure, the towel was actually slightly warmer than leaving my legs bare. That was right at sunset when there was no wind at all and the humidity was about 85%.
Fourth observation: A faint breeze makes the towels much more effective. Still too hot to sleep, I turned on a tiny little battery operated fan. Directing it over the towel made a big improvement in how cool I felt. After fifteen minutes my body temp was down to peaceful sleep levels and I needed neither towel nor fan.
Was the cooling towel valuable?
Well, I’m not going to get more of them. I’d considered a supply for The Place, or for the in-town house without power. The level of cooling isn’t worth the opportunity cost in terms of storage space and hassle of use, to me. Here’s why:
- When we most need cooling in Missouri, it’s also humid, and also often still. Towels work poorly in these conditions. In a desert environment, I might make another choice, except:
- Cooling towels use a lot of water. At least it needn’t be potable water.
- A wet kerchief isn’t as efficient, but a kerchief is much more multipurpose.
They might be worth it in areas of lower humidity and/or more breeze, where water was not limiting. Small children or older people, whose temperature control tends to be poor, might benefit from them as blankets that would keep off sun and bugs while reducing the risk of overheating.
An inexpensive idea/alternative
This was the response of one of my hiking partners to the challenge of walking in the hot sun all day long: A sun umbrella. It’s rather like a regular umbrella, but made of an especially sun-reflective fabric.
Benefits: Requires no water and is not impaired by high humidity or still air. It protects against sunburn. It would give some rain protection, too. This hiking partner was convinced it gave her real relief.
Drawbacks: Not much help on a hot night, is it? The bigger problem is that it uses up a hand; unless you’re sitting and set it to stay up by itself. The shade footprint isn’t that big. It’s a bit bulky to carry, and some weight (though not bad for its size). High winds are annoying.
I don’t like donating a hand to it; but if I had a baby to take care of I think this would be a good answer to provide shade without blocking breeze.
Note: We have no financial interest in any product related to this post.
- From figure by Wilfried Cordes (WilfriedC) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons
One thing that always annoyed me when I was doing manual labor in really hot weather, was sweat getting in my eyes and the nasty sticky feeling I got around my neck, especially when I was in the field with the military.
I found that the GI triangular bandages were perfect for sweat bands and neck bands. Soaking the neck band with water was even better. Perhaps not a perfect solution, but it made me feel a little bit better.
After a few washings, the cravats were very soft and comfy around the neck. On a sunny day, they took almost no time to dry. If you could, getting the edges hemmed was a good idea to keep them from fraying in the wash.
I still have four cravats well washed and hemmed. I used them a couple of years ago when a hurricane knocked out power at my place (albeit for only 21-hours, but they were still nice).
I keep a clean bandana in all my emergency bags; that’s one of its intended uses. I bet those triangular bandages are a little better size; especially for guys.
Looks like a No-Go on the Cooling Towels
Maybe a HUGE Bath Towel soaked down and laid out as a blanket at night????
Thanks for the “Range Report”
That’d sure be cool, if the patch of ground wasn’t sun-warmed and feel of it didn’t drive you nuts. Heaven knows nothing sucks body heat like damp bedding on cold ground.